Operating mechanism for electric switches



July 27, 1943. w w. EDSQN 2,325,382

OPERATING MECHANISM FOR ELECTRIC SWITCHES Filed Jan. 50, 1942 2 SheetsSheet l Inventor; William W. Edson,

b W TJMW y His Attorney July 27, 1943. W. w. EDSON 2,325,382

OPERATING MECHANISM FOR ELECTRIC SWITCHES Filed Jan. 50, 1942 2 Sheets-Sheet 2 Imventor; William W Edison,

y MAJ/519W His Attorney.

of load magnitude and frequently;

Patented July 27, 1943 23,25,382. OPERATING MECHANISMFOR' ELECTRIC SWITCHES WiHiamEW; Edson; Auburndale, Mass assignon to. Genet-ah Electric, Company, a corporation of- NewYork 7 Application January 30, 184.2, Serial No. 428 881 reclaims; V (or. 2o0 5c) My invention relates. to, improvementsin op erating mechanisms for electric and more particularlydisconnecting cw hes which. have a plurality of circuit controlling positions but which are not intended to intori 't currents. of'load magnitude;

'Inthe operation of so-callhdlow voltage net-- work distribution systems, itis desirable. to be ableto isolate frorn'thes stem cert'ai p i/maths; such" as the network .protecto poses of acement.

For 5'' Ch, isolationtherelias be the high'vo'lts e feeder side of the three posltion disconnecting switch in ti" ed on m a feeder. itself whereby the feeder can be connec ed to or disconnected from ti ehigh voltage windings the network transformer or connected directly to ground. Since for. reasons of econon y these switches are; not designed to interrupt currents:

even transformer magnetizing currents, they must not be operated while the transformer is energized. In other WOldS, these disconnectingswitches should'not be operated while the network protector is closed rwhile the circuit breaker at the supply end of the high voltageieeder is closed; or while both the network protector and theieeder circuitbreakcr are closed. For this purpose; it is customary to provide the disconnecting switch'with an electric interlock which. is intended to lockthe switch inwhatcver circuit controlling position it may be. at the time the tran'sformeris en rgized and to maintain the swltcbsin such position. as long as the transformer continues'to-be energized. But upon deenergization of the transformer in consequence otthe opening of the feeder circuit breaker at the statlcn'and. the network protector Where the disconnecting switchis-usually located, the locking action is temporarily discontinued so that the disconnecting switch maybe operated to disconnect; grounder reconnect the high voltage feeder; There is, however, always the possibility thatv the transformer may be re-energized' during the operationof the disconnecting. switch because, for example, someone at the remote end of. the fee may close the feeder circuit breaker. l even the neiw rkprotector may be closed by uhe usual relaying action if the person respons ble hasiaiIcdto take the necessary preca The. operation of the disconnecting switch is therefore subject to both personnel and equipment hazard-s;

In'or'der to avoid these hazards, it is common practice to arrange the disconnecting; switch so that in going from the open or disconnected position to the ground position or vice versa, it necessary to pass through, the on or transformerconne'ctedposition. This is done with the id'ea'that; if'the transformer becomes energized after leaving either the open position or' the ground position; the switch will'be-lockedwhen: it reaches the transformer. position; an'dno harm" should result. However; the switch locking a1- rans'ement, usually"electmmagnetic', requires a finite. time to function. Accordingly; in order to prevent the person operating-the switch from going through the open position or frcinthe-open position. through; the. transformer position to the ground position orvice versa too fast for the"- lccking mechanism to functiomthere. is provided some impediment to themovementof the switch in the open position and, also"; while passing through the transformer position from either the open position or the ground'position. These inrthe part of theoperatorastoihsurc enoughtime" for. the normal intended operation of" the locking mechanism if the transformer is energized:

One object of my inventionglstov providean-improved and simple switch' operating? mechanism whereby in operatingthe switch; it:is necessary to. go through the transformer position" While" going from the openposition-to the ground posi' tion or vice versa, and in so-doi'ng or-upongoing" through the open positiomthe operator is required to perform anoperatiomwhi'ch doesnot' produce a change-in the switch position but" does" cause enough time delay for the correct functioning of the locking mechanismto prevent, hazardous switching: Another-object, of. my invention is to provide an improvedswitch operating mechanism" which can be used a's'a rep1ace= ment for operating mechanisms'alreadyinstalled' so as to standardize and'thereby gain the benefits which accrue from standardlzatlcn. 'I'hcse'a'nd other objects of my invention-will appear'in more detailhereinafter;

My invention will bebetter understood fromthe. following description. when considered in connection with the accompanyingtwo sheets of drawings, and its scopewill"be"pointed" out in the appended claims. In the accompanyingdrawings, Fig;1'diagrammatically illustrates a part of an alternating'cufi rent network system embodying a switch" to which my invention. is applicable; Fig- 2; ilius trates in perspectivean embodiment of mY'lnvention arranged for one sequence of switching' operations; Fig; 3 illustrates in perspective an embodiment of my invention arranged for a a part of the so-called'network protector.

tion are adapted for the operation of disconnect ing and grounding switches, examples of which are well known to the art, and one of which is disclosed in United States Letters Patent 1,863,- 163 datedApril 28, 1931. As diagrammatically illustrated in Fig. 1, a three-phase disconnecting and grounding switch has three current conduct- 7 ing arms 6 and an operating crank '5, all of which are mounted on'the same shaft, indicated by a dot and dash line 8. The switch arms 6 are connected to the phase conductors S'of a feeder circuit and .in the position shown in fulllines, connect these conductors to ground. When the switch arms 6 are Vertical, the feeder conductors 9 are connected to the high voltage windings E9 of a transformer! i. .As shown, the low voltage windings i 2 of this transformer are connected to the network through suitable circuit interrupting means, such as a circuit breakeiiw, which forms extreme left,- position'of the'switch arms 6 indicated by the dot and dash 1iRS, T/he feeder phase conductors 9 are disconnectedffrom the trans former windings id. The disconnecting and grounding switch schematically illustrated diifers from that shown inthe above-mentioned patent m; that the transformer position is intermediate the open circuit position, represented by the dash and dot lines and th ground. position. 'The switch is also shown as provided with an electro- In the 2,325,382 H 7 I H in the art that the desired rotation of the'crank.

check the turning of' the member in aposition corresponding to a predetermined circuit controlling position of the switch, As'shown in Fig. 2, this guiding means comprises an arcuate, member, such as the curved plateZi which is preferably concentric with the shaft 8 and provided 7 with a trackway comprising two parallel passages or U magnetic interlock, such as :that illustrated in V the-above mentioned patent. This interlock in.- cludes an energizing winding '24 whichi connected across one of the phasewindings E2 of the I transformer l i. 'As shownthe winding is is an rangedto actuate a locking member E5 to engage any one of three notches in a cooperating lock- 7 ing member is which partakes of the movement of the shaft hand may be mounted directly thereon. The arrangement is such that as long as the transformer l i is energized the locking memberil tengages one of the notches the 00- operating member 13. to lock the switch against movement;

Referring now to th embodiment of-my invention shown in Fig. 2, a rotatable member such as theishaft 3" has mounted thereon an operating member such as the crank or handle lever 1 whereby the-shaft can be turned to a plurality of circuit controlling positions indicated as open,

transformer, and gro'und. "In accordance'with my invention, the cranli l is mounted for rotation with the shaft 3 and, also, relatively thereto. Thus, as shown in Fig, 1, the crank T-is mounted onapivotpin tlcarried in"an extension E8 on the shaft 8. A1so;in this specific embodiment of or openings such ,as slots 22 and 23 or the equivalent throughwhich'the crank? projects. In.

Fig; 2, the slot 23 is shown simply as a long notch since the spring 2% exerts no clockwise bias on the crank I'when it is positioned inthe notch 23. The slots 22 and 23 extend in a direction to permit rotation of the crank! with the shaft 8. Another slot Zrlinterconnects the two slots 22 and 23 and extends in a direction to permit the 'rotae tion of the crank i about its, pivot; H. Also, in

accordance with my invention, for delaying or checking the movement'lof the crank l in the" transformer position as itlis being moved from the open position, indicated by the dash-dot line 0, to the ground position or vice versa, the slot 22 I is. provided with 'a substantially perpendicular offset portion 25 which, like the slot 24, interpcses a' time action by requiring the operator o change. from one direction of rotation of the crank to another in going from one circuit controlling position of the switchto another.

For preventing the rotation of the crank 1 about its own axis while the crank; is in pre'de' termined positions and, also, for holding and locking the crank lin predetermined positions against rotation with the shaft,'I provide release able meanssuch as an eye member 26 which is pivotally secured to the crank 1 at 21. As shown,

this eye member is provided with a notched por-' 1 tion 28 which is arranged to engage with anyone of a plurality of projections 29, 3G, and 3|, respectively, corresponding ,to the ground, open,; and

my invention both this'extension and the pin H V are perpendicular to the shaft and to each other. This arrangement provides, in 'effect,ia yoke connection permitting the desired 'rotative movemerits of the crank. l. f It will be observed that,

since the'axes of the shaft 8 and the stemof the crank 1 intersect-movement of the crank relatively to the shaft, whenever such movement can occur, is always the plane determined by these two axes. n1 order to bias the crank 7 for rotationirl a predetermined direction about the pin H," the lower end of the stem'ofthis crank may have rigidly secured thereto a housing or stirrup portion 'IQ through opposite sides'of which the pin l'l extends; Suitableresflient means, such as acurved leafspring 29 secured to the crank l,

' bears against the shaft "extension is and tends 1 to turn the'crank i clockwise about its pivot l'i'.

It will, of course, be apparent to those'skilled transformer positions of the switch. ,In any one of thesepositions, an opening 32 cnthe member.

26 registers with an opening 33 in one of a plurality of lugs .34 on the plate 2| for the reception of a locking bolt or padlock, not shown. In orderto block the movement of the crank! in the slot 2%, the plate '25 may be provided with a lug 35 which is positioned in the path of movement of the member 25 when the crank l is rotated about its own axis while in the slot 2%.. In any one of the circuit controlling positions of the crank 1,.

the eye member 26 may be rotated upwardly about, its pivot 27! counterclockwise, as shown in the drawings, so as to be clear of the projections 29, 30, Si, and 35.

As shown'in Fig. 2, the crank T is in the ground position with the locking member 26 in engagement with the projectionz. If it'is desired to move the switch to anyother circuit controlling position, the lockingmember 26 must first be released from the projection 29 by rotatingit counterclockwise about its pivot 21. 'The crank 1 may,

then be turnedcounterclo'ckwise with theshaft 8. As the crank moves through the slot 22, rotation with the shaft 3 is arrested'when the crank comes into the cross slot25. It is then necessary for the operator of the switch to rotate the crank clockwise about its pivot I! in orderthat further counterclockwise movement of th'e' crank in the slot 22 may be effected. During the time required to change the'direction of rotation of the crank 1 by reason of the cross slot 25, the magnetic interiock referred to in connection with Fig. 1 is givenan opportunity to lock the shaft against further rotation if the transformer is energized when the crank is moved to the transformer circu'it closing position.- H the transformer is not energized; then further counterclockwise movement of the crank I may be made to the open position with the'crank' still in the slot 22. At this point, further rotation of the crank l with the shaft is arrested by the cross slot 24. If now it is desired to go from the open position to the final transformer circuit closing position, indicated by the dash-dotline T, this maybe accomplished if the member 26 is moved out of the way or the projection 35 and the crank I turned v clockwise about its pivot ll'until it is in the notch 23. During this clockwise movement of the crank T about its pivot ll, the magnetic lock referred to inconne'ction withFig. 1 has an opportunity to complete its locking action if the transformer is energized. If the transformer is not energized, then the crank 1 may be rotated clockwise with the shaft 8 to place the switch in the transformer circuit closing position. If it is desired to leave the switch in this position, then the member 26 may be turned clockwise about its pivot to engage the lug 3!, and the'member 28 may be further locked'to the projection 34 to prevent operation of the switch.

In the embodiment of my invention shown in Fig. he'sequence of the circuit controlling positions dilfersfrom that shown in Fig. 2 in that the open and transformer positions are interchanged. This change of positions requires a different arrangement of the plate 21,.which is shown with mounting lugs 36 whereby it can be secured to the switch housing or other support, not shown. Because of the angle of the perspective in Fig. 2, these lugs do not show. The trackway in the plate 2| of Fig. 3 comprises threeparallel openings, such as slots Si, 38, and 39, or the equivalent, the last of whichmay bea. notch. These slots extend in a direction to permit'rotation' of the crank l with the shaft 8. At the transformer position, the slots-37 and 38 are 43 which checks the counterclockwise rotation of the crank 1 with the shaft 8 and requires clockwise rotation of the crank 7 shaft 8 to the open position of the switch, indica by the. dash-dot line 0. This insures enough time delay in the transformer position for the operation of the electromagnetic interlock, not shown. Again, when the crank 1 reaches the open position, its clockwise rotation with the shaft 8 is checked by a cross slot til which interconnects the slot 38 andthe notch 39. To goto the transformer circuit closing position, it is necessary to rotate the crank 7 clockwise aboutits pivot l1 into the notch 39. This impediment again gives the electromagnetic lock time to function before the crank i can be rotated counterclockwise in thenotch B-Rwith the shaft 8 to the transformer circuit closing position, indicated line T. As before, the crank I may be retained in any of the circuit controlling positions by the eye member 25 and cooperating projections 29, 30, and Si on the plate 2|. Also, the shift between the slot 33 and the notch39 so as to go 'fromthe trackway in the interconnected by a cross slot.

about its pivot l1 before the crank can be rotated clockwise with the I by the dash-dot vice versamaybe blocked by'the lug 35 in conjunction'with the member 26. It will be observed that inthis modification of my invention the crank 1 may be m'oyedin 'th'e'slot 37 from the ground position through the open position of the tion of this embodiment of my invention will be apparent from the foregoing description,particularly when taken in conjunction with the explanation of the operation of the embodiment of my invention shown in- Fig. l. p

The embodiment of my invention shown in Fig.- 4 is; in general, similar to the arrangement shown in Fig. 2. In Fig. 4, the operating crank 1, again shown in the ground'position, is secured to a yoke member l9", which is pivotally secured to the shaft 8 at I? so that the crank 7 can rotate with theshaft 8 and in the plane determined by the shaft and the crank. Inthis embodiinent of my invention, the guiding means is particularly suited for casting and, as shown,

comprises a guiding memberi'l which is provided'with two parallel openings or passages, such as -slots 22 and 23, through which the crank projects. These slots extend in a direction to allow rotation of the crank I with the shaft 8.

Because of the change in angularity of the crank 1 relatively to the shaft 8, it is desirable to have the faces of the slots 22 and 23' suitably sloped in order that the crank may have a good full bearing sliding fit in these slots. Thus, if the crank 1 when in the slot 22' is perpendicular to the shaft 8, then the planes of the sides of the slot 22 should also be perpendicular to the shaft. Similarly, the angle between the planes of the sides of the slot 23 and the shaft 8 should correspond to the angle between the shaft and the crank I when the crank is in the slot 22. At the open position, the slots 22 and 23' are interconnected by a cross slot 24 which checks the rotation of the crank I with the shaft 8 but permits the rotation of the crank about the pin ll from either slot to the other.

Instead of offsetting the slot 22 to impede the movement of the crank l in going from the ground position through the transformer position to the open position and vice verse, I may provide other suitable checking means. As illustrated, this means is an open sided or slotted member 42 which is rotatably mounted between the ribs 43 and 44 of the guide member 2!. As shown, the-member 42 is in the form of a cylindrical bushing which is rotatable in a cylindrical bore 45 in and between the ribs 43 and 44 and is provided with a longitudinal opening 42 large enough to admit the stem of the crank l. The

bushing 42 is retained in position between the ribs 43 and 44 by its flange 46 and a slotted collar 41 which is suitably secured to the bushing 42 as by set screws 48. In order to rotate the bushing 42 in its cylindrical mounting in the guide member 2 l there is provided on the collar 41 a suitable projecting member 49.

For retaining the crank l V open-position to the transformer position and in any one of the three circuit controlling positions,'th'ere may be slot 23'.

ferator asi-o insure operation of the u v netic lock if the transformer is energized. The

provided a pluralityof holding members Eil one tion and there-retained bymoving its hook-en:

at each of the circuit controlling positions and each provided with a hook engagingportion for embracing the crank i. As shown, these holding;

members 56 are pivotally mounted on the guiding member 2!. [This is provided with a'plurality of locking openings 5i which register with cor-,

responding openings 52 in the holding members 50 when they;are in-position to engage the crank .1. These registering openings 51 and 52"may' accommodate" a suitable locking bolt or padlock, not shown. For blocking the movement of the crank I about its pivot pin, l'i from'the slot 22" tothe slot 23 and vice versa, I provide a suitably releasable blocking means which, as shown in Fig. 4, comprises a retractable bolt'53. This is mounted inthe guide member-2i and biased to the blocking position, shown, by-suitable means,

gaging member 53 to the holding position and locking it there. The reverse operation of the crank i will be obvious from the foregoing, and, of course,-it will be necessary to rotate the bushing d3 again in going from thee-pen position to V the ground position since there is no through While I have shown and described my invention in considerable detail, I donot desire to be modifications that fallwithin the true spirit and such as, a spring 54. The blocking'member may be moved to the released position by pulling outwardly on a handle member 55. V

For mounting the guidingmember on the side of the switch housing 55, it may comprise a plurality of angle extensionsiil which connect, to a common supporting part 7 58, "Suitable means, such as bolts 59, serveto fasten the supporting part'58 against a bearing plate 69 on the housing. Since :switches of thejtype for] which my. operating handle is particularly in-.

tended usually operate in an insulating fluid, it is customary to provide. suitable fluid retaining means, such as a bushingfil through which the shaft 8 passes and whichds suitably adjustable with respecttoi'the housing '55 as by screws .62.

Assuming the parts positioned as shown in Fig.

4, thenthe crank 'i may be released-by turning the holding member at the ground position out of the-holdingposition shown sothat its h0ok-shaped part is disengagedfroin the crank The'crank l may then be rotated in the slot '22-" counterclockwise with the shaft 8 into the longitudinal slotted opening of the bushing 52 if the bushing is in the'position shown. Otherwise, it must befirst turned to this position by.

means of the actuatinguprojection 49; When the crank] moves into the bushing eZ,-ncfurther 7 counterclockwise rotationwith the shaft dispossible untilfthe bushing 42 igturned 186?. =This i accomplished by pushing or pulling on the operating projection 28.

open the transformer circuit. This delayed ac tion, by'virtue of thenecessity of having to turn thebushing 52,- through an angle sufiicient to per;

mit, the rotationoi the counterclockwise move. merit of the crank i, issuilicient to give the electromagnetic lock, not shown, time to function if r the transformer is energized. If the transformer is not energized, then the counterclockwise movement of the crank] with the shaft 8 maybe con- Thus, with the" crank in the transformer position, there i interposed a time delay before the crank lean begmoved to:

" ling position of the switch.

limited to the exactarrangements shown,l but seek to cover in the appended claims all those scope of my invention.

. WhatI claim as new anddesire to secure by' Letters Patent of the United States is:

1'. .In.a n operating mechanism for'an" electric witch having a plurality of difierent circuit controlling positions, a rotatable member, means for turning said rotatable member comprising an operating member mounted on said rotatable member for rotation therewith and, also, relatively thereto, and guiding means for-said operating member constructed and arranged to permit only one-;-of the two difierent rotative movements thereof at a time and both movements in a pre-' determined sequence whereby to check the turn-j ing of said rotatable member in a position cor-- responding to a predetermined circuit control- 2.111 an operating mechanism for a-n'electric switch havin a plurality of difierent circuit controlling positions, a'rotatable memben'means for turningsaid rotatable member comprising an op- 1 crating member mounted on said rotatable memher for rotation therewith and, also, relatively thereto, guiding means for said operating-mam ber constructed and arranged to permit the two different rotative movements thereof in a predetermined sequence whereby-to check the turning of said rotatable member in, a position'corresponding to a predetermined circuit controlling position-of the switch, and cooperating means on said guiding means and said'operatin'g member adapted to be operated to retain the-operat ing member in, predetermined positions.

'3. In an, operating mechanism for an electric switchhaving a plurality of difierent'circuit'controlling positions, a rotatable'member, means for turning said rotatable member comprising anopcrating member mounted on said rotatable memtinued to the open position where the shaft Ino- 1 tion is arrested when the crank comes to rest Before goingto the a at the end of the slot 22. final transformer position where the switch crank i ordinarily left locked, it is necessaryto' with draw the blocking member 53 bypulling on the handle 55 and then to rotate the crank l clockwise'about'its pivot ll until the crank i in the These movements interpose'adelay and require suchlforethought on the part of the op;

electromagcrank fl may then be rotated-clockwise in the 7 slot 23' with the shaft .8 tothe transformer posi tion of the rotatable member the rotation ber for rotation therewith and, also, relatively theret 'guiding means forsaid operating member constructed and arranged to permit the two trolling positions, ashaft, means for'turning said shaft comprising a crank mounted on said shaft for rotation with the shaft and relatively thereto,and a guide plate having a plurality of openingsin whichsaid'crank is movably positioned, at least two of said openings being substantially parallel and extending in a-direction to permit rotation of said-crank only with the shaft and another ofsaid openings interconnecting. said passage in the bushing and its associated collar of the two openings and extending in a direction to permit rotation of said crank relatively to the shaft.

5. In an operating mechanism for an electric switch having a plurality of different circuit controlling positions, a shaft, means for turning said shaft comprising a crank pivotally mounted on said shaft for rotation with the shaft and about an axis substantially perpendicular to the axis of rotation of the shaft, a guide plate having a plurality of openings in which said crank is movably positioned, at least two of said openings being substantially parallel and extending in a direction to permit rotation of said crank only with the shaft and another of said openings interconnecting said two openings and extending in a direction to permit rotation of said crank only about its own axis, and releasable means on said guide plate for preventing rotation of the crank about its own axis while the crank is in the interconnecting opening.

6. In an operating mechanism for an electric switch having a plurality of different circuit controlling positions, a rotatable member, means for turning said rotatable member comprising an operating member mounted on said rotatable member for rotation therewith and, also, relatively thereto, and means for guidin the rotation of said operating member with said rotatable member from a first circuit controlling position to a second circuit controlling position and thence through said first circuit controlling position to a third circuit controlling position and vice versa including means requiring the rotation of said operating member relatively to said rotatable member while going through said second circuit controlling position in either direction, and means for impeding the movement of the operating member at the first circuit controlling position while going from the second circuit controlling position to the third circuit controlling position and vice versa.

'7. In an operating mechanism for an electric switch having a plurality of different circuit controlling positions, a shaft, means for turning said shaft comprising a crank pivotally mounted on said shaft for rotation with the shaft and about an axis substantially perpendicular to the axis of rotation of the shaft, and means for guiding the rotation of said crank with the shaft in one direction from a first circuit controlling position to a second circuit controlling position and in the reverse direction from said second circuit controlling position through said first circuit controlling position to a third circuit controlling position and vice versa including means requiring rotation of the crank about its own pivotal axis before changing the direction of rotation of the shaft in the second circuit controlling position, and means for impeding the movement of the crank at the first circuit controlling position while going from the second circuit controlling position to the third circuit controlling position and vice versa.

8. In an opening mechanism for an electric switch having a plurality of different circuit controlling positions, a shaft, means for turning said shaft comprising a crank pivotally mounted on said shaft for rotation with the shaft and about an axis substantially perpendicular to the axis of rotation of the shaft, and means for guiding the rotation of said crank with the shaft in one direction from a first circuit controlling position to a second circuit controlling position and in the reverse direction from said second circuit controlling position to said first circuit controlling position and thence in said reverse direction to a third circuit controlling position and vice versa including means requiring rotation of the crank about it own pivotal axis before each change in the direction of rotation of the shaft and in going from the first position through the second position to the first position and from the second position through the first position to the third position and vice versa.

9. In an operating mechanism for an electric switch having a plurality of different circuit controlling positions, a shaft, means for turning said shaft comprising a crank pivotally mounted on said shaft for rotation with the shaft and about an axis substantially perpendicular to the axis of rotation of the shaft, and means for guiding the rotation of said crank with the shaft in one direction from a first circuit controlling position to a second circuit controlling position and in the reverse direction from said second circuit controlling position to said first circuit controlling position and thence in said reverse direction to a third circuit controlling position and vice versa including means requiring rotation of the crank aboutits own pivotal axis before changin the direction of rotation of the shaft in the second circuit controlling position, and means for impeding the movement of the crank at the first circuit controlling position while going from the second circuit controllingposition to the third circuit controlling position and vice versa.

10. In an operating mechanism for an electric switch having a plurality of circuit controlling positions, a rotatable member, an operating member joined to said rotatable member and movable therewith and relatively thereto in a plane determined by the axes of said rotatable and operating members, and guiding means for said operating member requiring movement thereof only in such plane in a predetermined circuit controlling position of said switch whenever the switch is actuated through such predetermined circuit controlling position.

11. In an operating mechanism for an electric switch having a plurality of circuit controlling positions, a rotatable member, an operating member arranged for rotation with and relatively to said rotatable member, and guiding means for said operating member constructed and arranged to permit rotation only of the operating member in a predetermined circuit controlling position of said switch whenever the switch is actuated through such predetermined circuit controlling position.

12. In an operating mechanism for an electric switch having a pluralit; of different circuit controlling positions, a shaft, means for turning said shaft comprising a crank pivotally mounted on said shaft for rotation with the shaft and relatively thereto, and means for guiding the rotation of. said crank with the shaft in one direction from a first circuit controlling position to a second circuit controlling position and in the reverse direction from said second circuit controlling position to said first circuit controlling position and thence in said one direction to a third circuit controlling position and vice versa including means requiring rotation of the crank about its own pivotal axis in going from the first position to the second position and through the second position prior to rotation of the shaft in said reverse direction through the first position to the third position and vice versa.

WILLIAM W. EDSON. 

